complex numbers

[scrapster]

write the complex number in rectangular form
7(cos270degrees + i sin 270 degrees)

[OfficeShredder]

It's easy. Just find cos(270) and sin(270), and you're done. A calculator will do the job, but you really should be able to figure it out in your head (if you get stuck, draw a unit circle and find 270 degrees)

[HallsofIvy]

Are you saying you do not know how to find cosine and sine of 270 degrees? If so, do you know where 270 degrees from the positive x-axis is on a graph?